Low graft function linked to increased mortality

Among kidney transplant recipients in stable condition, lower levels of kidney function are independently associated with mortality risk, according to a report in the American Journal of Transplantation.

The authors performed a post hoc analysis of a trial evaluating the effects of homocysteine-reducing B vitamins after kidney transplantation. The analysis included 4016 patients, mean age 52 years, 20 percent with a history of cardiovascular disease (CVD). Estimated GFR (eGFR) was evaluated for associations with incident CVD and all-cause mortality, adjusted for demographic factors, clinical and transplant characteristics, and traditional CVD risk factors.

Complete data were available for 3676 patients, who had 527 CVD events over a median follow-up time of 3.8 years. In the adjusted model, below a cutoff point of 45 mL/min/1.73 m2, higher eGFR levels were associated with reduced risks of CVD and death. For both outcomes, the hazard ratio was 0.85 for each 5 mL/min/1.73 m2 increase in eGFR. No association was present at eGFR levels of 45 mL/min/1.73 m2 or higher.

Although CVD is the main cause of mortality after kidney transplantation, it has been unclear how kidney function affects posttransplantation CVD outcomes. This study finds that below 45 mL/min/1.73 m2, higher eGFR levels are independently associated with a lower incidence of CVD and a lower risk of death. “[R]educed kidney function itself rather than preexisting comorbidity may lead to CVD,” the researchers conclude [Weiner DE, et al. Kidney function and risk of cardiovascular disease and mortality in kidney transplant recipients: the FAVORIT trial. Am J Transpl 2012; 12:2437–2445].